JPH089465Y2 - Disc brake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a disc brake used in a vehicle or the like.

(Prior Art) Pads used for disc brakes are required to withstand high surface pressure, high load, and high temperature, and raw materials having high wear resistance and heat resistance are used.

For this reason, asbestos-resin mold systems, in which asbestos is used as the base material and combined with binding resins and various friction modifiers, have been the mainstream, but in recent years, metal wires have been used as the base material in consideration of dust pollution and life improvement. Semi-metallic and metallic types have been used.

However, when a metal pad is used, since the disc is also made of metal, a spark is generated during pressure contact. If the spark adheres to the piston boot of the disc brake, the piston boot deteriorates and is damaged.

Therefore, conventionally, there is one in which a shim provided between the back metal of the inner pad and the piston is extended in the radial direction of the disc to form a shield plate, and this shield plate prevents sparks from coming in (actually developed. 63-49032 publication).

(Problems to be solved by the invention) However, in the above-mentioned conventional disc brake provided with a shield plate, it is necessary to set a certain gap between the shield plate and the caliper. In other words, the position of the shield plate shifts as the lining wears, so if there is a molding slope or step on the caliper, it is necessary to secure a gap so as not to interfere with the position of the shield plate when they shift. Yes, and since calipers are usually manufactured by casting,
It is necessary to secure a gap with the shield plate so that dimensional accuracy cannot be expected and assembly failure will not occur.

Therefore, sparks generated when the pad is pressed against the disc may fly to the piston boot side through the gap set between the shield plate and the caliper,
There was not sufficient shielding.

Also, when the brake has a high load, that is, when the pad is pressed against the disc with a large force, the scraped metal powder ignites, and the flame enters the piston boot side and burns the piston boot. There was also a problem.

Generally, an elastic material or the like is used for the shim forming the shielding plate, but if the shim is an elastic material or is coated with an elastic material, its processing has a certain limit. However, the material was extremely limited, and the versatility was low.

An object of the present invention is to provide a disc brake capable of reliably preventing damage to a piston boot without being restricted by materials and the like.

(Means for Solving the Problems) As means for solving the above problems and achieving the object, a cylinder portion having a piston for pressing an inner pad, and an outer pad arranged to face the inner pad with a disc in between are pressed. The inner pad and the back pad of the inner pad, which includes a caliper formed of a bridge portion connecting the cylinder portion and the claw portion across the claw portion and the disk, and a caliper support pin that slidably supports the caliper with respect to the carrier. In a disc brake provided with a shim between the pressing portion of the piston and a piston boot that protects a sliding portion between the cylinder portion and the piston, the shim includes a shim main body, and the shim main body includes the inner shim. A cover shim that is sandwiched between the back metal of the pad and the bridge portion of the back metal of the inner pad. An intermediate portion extending parallel to the end surface facing the disk, and extending toward the disc side to the joint between the backing metal of the inner pad and the lining, and an end portion of the intermediate portion that is bent and extends parallel to the disc. It is characterized in that a shield plate having a shield portion whose end portion is located in the vicinity of the opening formed in the bridge portion is provided.

(Operation) With this configuration, the shield plate comes close to the position where the disk and the pad where sparks or flames are generated are in contact with each other.
Therefore, the generated sparks and flames can be removed before they spread significantly, and the amount of entering the piston boot side can be reduced.

Further, since the shielding plate has a heat insulating effect, the temperature on the piston boot side is relatively low. further,
The distance from the shield plate to the piston boot becomes longer as the shield plate comes closer to the position where the disc and the pad contact each other. Therefore, sparks and flames that enter through the gap between the shield and the caliper are cooled between the shield and the piston boot.

In this way, deterioration of the piston boot is prevented. Furthermore, as described above, the shield plate that prevents sparks from adhering to the piston boot is formed on the cover shim that is separate from the shim body, so the material of the shim body is not limited and a wide selection of materials can be performed. In addition, the shielding plate can be easily processed by selecting and using a material having excellent processability.

(Embodiment) Next, an embodiment of the present invention will be described with reference to the drawings.

First, referring to FIG. 1, the disc brake 1 of the present embodiment.
To explain the configuration of the above, a caliper 3 is held by a carrier 2 fixed to a rotated member of the vehicle by a caliper support pin (not shown) so as to be movable in the axial direction of the disc 4. A cylinder portion 5 is formed on the caliper 3,
A piston 6 is slidably provided on the cylinder portion 5. In addition, reference numeral 7 in FIG. 1 denotes a piston boot that protects the sliding portion between the cylinder portion 5 and the piston 6 from entering dust and water.

Further, a bridge portion (reference numeral omitted) that straddles the disk 4 is formed on the caliper 3, and a claw portion 8 is formed on the tip side of this bridge portion. The piston 6 is in contact with the inner pad 9 via the shim 10, and the caliper 3
The bridge portion 8 is in contact with the outer pad 11 via the shim 12.

The inner pad 9 and the outer pad 11 are each composed of a lining 13, 14 and a back metal 15, 16. Sim 1
0 and 12 are for preventing "squeaking" during braking, and each has a back metal
Installed on 15,16.

Reference numeral 17 in FIG. 1 is an opening formed in the caliper 3 and is provided to check the degree of wear of the linings 13 and 14.

In this structure, when the piston 6 moves forward (moves to the right in FIG. 1), the caliper 3 relatively moves in the direction opposite to the piston 6, and the disc 4 is held between the inner pad 9 and the outer pad 11. Generates power.

Next, the structure of the inner pad 9 will be described with reference to FIGS. 2 and 3.

The shim 10 includes an elastic body shim 18 and a cover shim 19,
The elastic shim 18 is attached to the back metal 15, and further has a protrusion 20 protruding in the direction opposite to the disc 4.
Further, the cover shim 19 is formed with an engagement hole 21 into which the protrusion 20 of the elastic body shim 18 is fitted, and elastic leg portions 22 at both upper and lower ends.

The cover shim 19 is attached to the back metal 15 while sandwiching the elastic shim 18 by sandwiching the back metal 15 between the upper and lower elastic leg portions 22.

Shield plates 23 and 24 are formed above and below the cover shim 19, and the shield plates 23 and 24 are provided at positions corresponding to the portions where the piston boot 7 protrudes from the back metal 15.

The upper shield plate 23 includes an intermediate portion 25 extending toward the disc 4 in the axial direction of the disc 4, and a shield portion 26 that is bent at a predetermined position and extends outward in the radial direction of the disc 4. The end of the shield portion 26 is located at the peripheral edge of the opening 17 of the caliper 3 in a state where the lining is not worn.

Further, the lower shield plate 24 is extended inward in the radial direction of the disc 4, and a bent portion 27 is formed at the tip end thereof by being bent in the disc 4 direction.

The operation of this configuration will be described. Sparks and flames generated by the inner pad 9 and the outer pad 11 being pressed against the disk 4 hit the upper shield plate 23 and the opening portion of the caliper 3 is opened.
It is discharged from 17 to the outside. Further, since the shielding plate 23 is close to the position where the disc 4 which is the place where the spark or flame is generated and the lining 13 of the inner pad 9 are in contact with each other, the generated spark or flame is wiped off before it spreads greatly. Therefore, the amount of sparks and flames that enter the piston boot 7 side through the gap between the shield plate 24 and the caliper 3 is significantly reduced.

Also, the piston boot 7 is insulated by the shield plate 23.
The temperature on the side is relatively low, and the distance from the shield plate 23 to the piston boot 7 is longer because the shield plate 23 is closer to the position where the disc 4 contacts the lining 13 of the inner pad 9. Therefore, the sparks and flames that have entered through the gap between the shielding plate 23 and the caliper 3 are cooled in the meantime.

In this way, the amount of sparks and flames entering from the shielding plate 23 to the piston boot 7 side is reduced, and the entering sparks and flames are also cooled on the piston boot 7 side, so the sparks and flames of the piston boot 7 are reduced. It is possible to prevent damage due to.

Further, as described above, the shield plate 23 for preventing the sparks from adhering to the piston boot 7 is provided with the elastic shim (the shim body).
Since the cover shim 19 is formed separately from the cover shim 18, the material of the elastic shim 18 is not limited to a wide range, and a wide range of materials can be selected. It can be easily processed.

In this embodiment, sparks and flames tend to fly outward in the radial direction of the disk 4 due to centrifugal force, so the lower shield plate 24 is simply bent at its tip as in the conventional case. The shape may be the same as that of the upper shield plate 23.

If the end portion of the shield portion 26 of the shield plate 23 is bent toward the disc 4 side in the axial direction of the disc 4 and extended by 2 to 3 mm, the worn state of the lining 13 can be understood with reference to the tip portion thereof. The replacement time of the pad 9 can be judged at a glance from the opening 17 of the caliper 3.

(Effect of the Invention) As described in detail above, the present invention is generated at the contact portion between the pad and the disc for preventing deterioration of the piston boot due to sparks or flames generated when the pad is pressed against the disc. When a spark or the like collides with the shield, the shield extends in parallel with the disk and guides the spark or the like toward the opening side. The sparks do not swirl and stay, and the amount of sparks and flames that enter the piston side can be reduced, and the shield plate comes close to the position where the disk and pad where the sparks and flames occur are in contact with each other. The sparks and flames can be blown off before the sparks and flames that have spread greatly, and the amount of sparks and flames that enter the piston boots can be further reduced to prevent damage to the piston boots. Further, the cover shim has an intermediate portion that extends parallel to an end surface of the back metal of the inner pad facing the bridge portion and extends toward the disc side toward a joint between the inner metal of the back metal and the lining, and the intermediate portion. A shield plate is provided, which is formed by bending the end portion and extends parallel to the disk, and the end portion of which is located near the opening formed in the bridge portion. Since the heat capacity and heat dissipation of the entire shield plate are excellent, the friction heat of the pad can be dissipated more quickly.

Further, since the shielding plate is integrally formed from the shim, the number of parts and assembling steps do not increase, and the cost does not increase. In addition, as described above, the shield plate that prevents sparks from adhering to the piston boot is formed on the cover shim that is separate from the shim body, so the material of the shim body is not limited and a wide range of materials can be selected. In addition, the shielding plate can be easily processed by selecting and using a material having excellent processability.

[Brief description of drawings]

1 is a longitudinal sectional view of a disc brake according to an embodiment of the present invention, FIG. 2 is a perspective view of a pad used in the disc brake shown in FIG. 1, and FIG. 3 is shown in FIG. It is an exploded perspective view of a pad. 4 ... Disc, 6 ... Piston 7 ... Piston boot, 9 ... Inner pad 19 ... Cover shim, 23 ... Shield plate 25 ... Middle part, 26 ... Shield part

Continuation of the front page (56) Reference JP-A-58-156731 (JP, A) Actually opened 56-7132 (JP, U) Actually opened 63-82832 (JP, U) Actually opened 57-59221 (JP , U) Sukeko Sho 62-29704 (JP, Y2)

Claims (1)

[Scope of utility model registration request] 1. A cylinder part having a piston for pressing an inner pad, a claw part for pressing an outer pad arranged to face the inner pad with a disc in between, and the cylinder part and the claw part for straddling the disc. A caliper formed of a bridge portion and a caliper support pin that slidably supports the caliper with respect to the carrier are provided, and a shim is provided between the back metal of the inner pad and the pressing portion of the piston, and the cylinder portion and the In a disc brake provided with a piston boot that protects a sliding portion with a piston, the shim is composed of a shim body and a cover shim sandwiching the shim body between the inner pad backing metal,
An intermediate portion that extends parallel to the cover shim along the end surface of the back metal of the inner pad facing the bridge portion and extends toward the disc side toward the joint between the back metal of the inner pad and the lining, and the end of the intermediate portion. A disc brake, which is formed by bending a portion thereof, extends in parallel with the disc, and has an end portion which is a shield portion located in the vicinity of the opening formed in the bridge portion.